E30 Zone

Hi all i may well be buying a 320i for which im gonna use as a daily and for a bit of drifting, now i am wanting to swap the engine to the m25, i had one before which was converted and was a very cheap car to run as well as being plenty fast enough, now i know you can fit the 535i engine in also so would this be a better option in the long run and how much would that cost/difficulty in comparison to the m25?? thanks

M20B20 swap for M20B25, the first option you mentioned is a relatively easy swap. If the the subframe is still attached, the whole lot can be dropped out of the bottom of the car and replaced with the 2.5 engine and its upgraded suspension at the same time.

The M30 535i engine is a lot more involved. Check out the M30 section and the conversion guide.